Myogenic activation of isolated small arteries (200-500 microns) of the dog kidney was evaluated by measuring vessel diameters during stepwise elevations of transmural pressure before and after removal of the endothelium by mechanical rubbing or air perfusion. Myogenic activation was unaffected by mechanical rubbing, but air perfusion caused the arteries to constrict and attenuated the myogenic response; i.e., vessel diameters increased as transmural pressure was elevated. However, air-perfused arteries still constricted in response to norepinephrine and dilated during superfusion with Ca(2+)-free solution, demonstrating that loss of the myogenic response did not result from an inability of the vessel to contract. Intact arteries contracted with 1 microM norepinephrine exhibited normal myogenic responses, demonstrating that loss of myogenic activation in the air-perfused vessels was not a nonspecific effect secondary to constriction of the artery. These results suggest that myogenic activation of small renal arteries is independent of the endothelium and that the method of endothelial removal may affect conclusions regarding the role of the endothelium in mediating the myogenic response.

Two eye-movement experiments are reported in which a boundary paradigm was used to manipulate the presence versus absence of boundaries for high-frequency and low-frequency target words in the parafovea. In Experiment 1, this was done by introducing a blank space after the target words, whereas in Experiment 2 this was done by rendering the target words in red. In both experiments, higher frequency targets engendered longer saccades, whereas the presence of parafoveal word boundaries engendered shorter saccades. This pattern suggests the operation of two countermanding saccade-targeting mechanisms: one that uses parafoveal processing difficulty to adjust saccade lengths and a second that uses word boundaries to direct the eyes toward specific saccade targets. The implications of these findings for models of eye-movement control during reading are discussed, as are suggestions for integrating dynamic-adjustment and default-targeting accounts. Keywords Chinese reading. Dynamic-adjustment model. Eye-movement control. Word segmentation Skilled reading requires the coordination of lexical processing with eye movements to rapidly extract visual information from the printed page. One important aspect of this coordination is saccade targeting, or the Bdecisions^about where to move the eyes. Because much of what has been learned about eyemovement control in reading has come from studies involving alphabetic writing systems, models of how readers decide where to move their eyes have been informed largely by what has been learned from studying languages like English and German, where the eyes seem to be directed toward a small number of default targets (e.g., see Engbert, Nuthmann, Ricter, & Kliegl, 2005; Reichle, Pollatsek, & Rayner, 2012). For example, with English, readers seem to direct their eyes slightly to the left of a word's center, toward the preferred-viewing location (PVL;

The mechanical properties of poly (lactic acid) (PLA) nanofibers with 0%, 5%, 10%, and 20% (w/w) poly (vinyl alcohol) (PVA) were investigated at the macro- and microscale. The macro-mechanical properties for the fiber membrane revealed that both the modulus and fracture strain could be improved by 100% and 70%, respectively, with a PVA content of 5%. The variation in modulus and fracture strain versus the diameter of a single electrospun fiber presented two opposite trends, while simultaneous enhancement was observed when the content of PVA was 5% and 10%. With a diameter of 1 μm, the strength and toughness of the L95V5 and L90V10 fibers were enhanced to over 3 and 2 times that of pure PLA, respectively. The structural evolution of electrospun nanofiber was analyzed by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). Although PLA and PVA were still miscible in the concentration range used, the latter could crystallize independently after electrospinning. According to the crystallization behavior of the nanofibers, a double network formed by PLA and PVA—one microcrystal/ordered structure and one amorphous structure—is proposed to contribute to the simultaneous enhancement of strength and toughness, which provides a promising method for preparing biodegradable material with high performance.

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Background Few population studies have described the heritability and intrafamilial concordance of the retinal microvessels, or the genetic or environmental correlations of the phenotypes of these vessels.

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